There is a need for improved technologies for processing the surfaces of substrates. Photovoltaic (PV) devices, for example, are typically fabricated by depositing thin film layers of various materials, such as silicon and metal, on a substrate material, such as a glass sheet, to form a solar cell.
PV devices are not yet cost competitive with fossil fuels. Currently, the manufacturing of PV devices is based on technologies originally developed by the semiconductor industry. Semiconductor chips are extremely sophisticated, but have a small area (˜1 cm2). By contrast, photovoltaic devices are relatively simple devices with a very large area. The technologies developed to create 108 transistor chips are not necessarily well-suited to the production of a single large diode, i.e. a PV cell. Nonetheless, chip technologies are currently being dimensionally scaled for PV production. Current PV manufacturing tools employ high-vacuum technology, and sequentially transfer large sheets of glass from chamber to chamber, coating the glass substrates with layers of silicon and metal to form the solar cells. This so-called batch processing approach is not consistent with high-volume, low-cost manufacturing.